UDF – Function to Parse AlphaNumeric Characters from String

CREATE FUNCTION dbo.UDF_ParseAlphaChars
(
@string VARCHAR(8000)
)
RETURNS VARCHAR(8000)
AS
BEGIN
DECLARE @IncorrectCharLoc SMALLINT
SET @IncorrectCharLoc = PATINDEX('%[^0-9A-Za-z]%', @string)
WHILE @IncorrectCharLoc > 0
BEGIN
SET @string = STUFF(@string, @IncorrectCharLoc, 1, '')
SET @IncorrectCharLoc = PATINDEX('%[^0-9A-Za-z]%', @string)
END
SET @string = @string
RETURN @string
END
GO

—-Test
SELECT dbo.UDF_ParseAlphaChars('ABC”_I+{D[]}4|:e;””5,<.F>/?6')
GO

Result Set : ABCID4e5F6